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Showing posts with label pure water. Show all posts
Showing posts with label pure water. Show all posts

Friday, December 18, 2015

Decarbonizing Planet Earth with Carbon


“The method adopted in Vedanta to impart the knowledge of Brahman is known as the method of superimposition (adhyaaropa) and subsequent negation (apavaada). In the Bhashya, Bhagavatpada says, “The transmigrating self is indeed Brahman. He who knows the self as Brahman which is beyond fear becomes Brahman. This is the purport of the whole Upanishad put in a nutshell. It is to bring out this purport that the ideas of creation, maintenance and dissolution of the universe, as well as the ideas of action, its factors and results were superimposed on the Self. Then, by the negation of the superimposed attributes the true nature of Brahman as free from all attributes has been brought out. This is the method of adhyaaropa and apavaada, superimposition and negation, which is adopted by Vedanta.” (Ref: What are Upanishads? : An over view by S.N. Sastri on Luthur.com) The analogy that is often used to describe the process of superimposition and negation is that of ‘using a thorn to remove a thorn’. Finally, when the last thorn is removed, the thorn used to remove it is thrown away as well. Similarly, Carbon can be used to reduce carbon emission while power is generated! Let us consider the issues of Carbon emission and global warming resulting in climate change in the above context. Recent conference in Climate change held in Paris is acclaimed to be a success to the planet earth collectively adopted by 195 countries both developed and developing. In a nutshell they all have agreed to reduce their carbon emissions to limit the global warming to less than 2C or even 1.5 between 2030 and 2050. Is it really practical to achieve the above target given the nature of reduction and the complexity of imposing such a reduction within the time frame? It is a big question mark. The only practical method to reduce CO2 is by using Hydrogen CO2 + H2----> CO + H2O and then convert CO into a useful product such as Urea NH2CONH2 a fertilizer. Production of Urea requires additional Hydrogen which is again obtained by combustion of fossil fuel resulting in CO2 emission. Moreover, CO2 will eventually be released at the point of usage of urea later. While trying to reduce Carbon emission one will end up with more Carbon emission in the atmosphere.
The carbon emission from power plants can be substituted with renewable energy sources such as wind and solar at a very high cost but how the emissions from chemical plants such as urea or from automobile emissions, steel plants and cement plants be contained? We should also remember that silicon wafer to produce solar panels consume large amount of power which now comes invariably from fossil fuels. There is a long list of such plants emitting Carbon every day from all over the world. But there is a possibility to reduce emissions substantially by converting CO2 emissions from power plants into a synthetic fuel which can then substitute fossil fuel to continue power generation. The CO2 resulting from combustion of synthetic fuel will be recycled in the same manner mentioned above thus completing a cycle. To convert CO2 into a synthetic fuel we will require Hydrogen either by renewable sources or non-renewable sources. The non-renewable sources for Hydrogen cannot be a long term solution but renewable Hydrogen is very expensive at this stage. Therefore, Hydrogen is the only source which will not only help reduce Carbon emissions but also help eliminate Carbon completely from planet earth. Renewable Hydrogen is the key to decarbonize the planet earth. However, it may be possible to decarbonize the planet temporarily by using Hydrogen derived from fossil fuel without emitting CO2! It is not just a theory but practical because the technology has already been tested! In this process the Carbon will remain in the loop where it will neither be buried nor emitted into the atmosphere but constantly recycled.

Monday, February 27, 2012

Water- Fuel of the future

Water constitutes 71% of the planet earth and it is the most potential energy source of the future. Water is a product of combustion between Hydrogen and Oxygen, two most abundantly available elements and vital for life on earth. The bondage between Hydrogen and Oxygen is so strong that it requires certain amount of energy to separate them. Separation of Hydrogen and Oxygen using the process of Electrolysis is a well known technology. Separation of water by high temperature using Thermolysis has also been studied. In both the processes the separation of Hydrogen and Oxygen after decomposition is a key step because of the strong affinity between the two elements. Hydrogen has to be separated in a pure form without any trace of Oxygen. Currently most of Hydrogen is generated commercially by steam reforming natural gas because of its easy availability as piped gas in many developed countries. Moreover steam reforming is a well established commercial technology that has been used for decades in chemical process industries. The hydrogen resulting from steam reforming is acceptable for combusting in Hydrogen internal combustion engines but not pure enough for a Fuel cell car. Any trace of impurity from natural gas such as Sulfur or mercaptans can potentially poison the catalyst used in fuel cell which is very expensive. Hydrogen with purity less than 99.99% is not recommended for Fuel cell applications. Currently there are few issues to be addressed before Hydrogen becoming a commercial fuel. The energy required to separate Hydrogen from water by commercial electrolysis is about 6Kws (kilowatts) to generate 1 m3 (cubic meter) of Hydrogen. Two key factors for electrolysis are purity of water and DC power source. Water of certain purity is a critical component for Hydrogen generation. Deionized water with electrical conductivity less than 0.10 micro Siemens/cm is required. Normal drinking water conductivity is less than 100micro Siemens/cm. The potable water can be deionized with reverse osmosis system to get necessary quality. In fact both high purity water and direct current are not commercially available. A renewable energy sources such as solar or wind that generates direct current can be used for electrolysis. This will eliminate batteries and rectifiers that we normally use in renewable energy systems. The generated Hydrogen can be stored in cylinders under high pressure. The stored hydrogen is the stored energy that can be used as and when required. We can use the stored Hydrogen to generate electricity to meet our power requirement whether it is a home or business or industry. The major advantage with this system is that we can generate power whenever we need and we don’t have to depend on the grid power. We can also export surplus power to the grid. In fact all DC appliances can be connected with DC power from Fuel cell and operated to improve the efficiency. Such a system is ideal for remote locations without any grid supply such as remote villages or islands. The same stored Hydrogen can also be used as fuel for a car whether it is a combustion engine or a Fuel cell car. Hydrogen can be compressed and stored under high pressure. Alternatively, Hydrogen can be stored using metal hydrides in smaller volumes. Honda introduced the first fuel cell car in the market in 1999. Since then they have made considerable improvements. Honda FCX Clarity, sedan offers a mileage of 270 miles for a single cylinder of Hydrogen at 5000 psi pressure. They are introducing a latest model with Hydrogen pressure at 10,000 psi which will considerably improve the mileage further. Unlike Hybrid cars, Fuel cell cars run silently and experts who have test-driven the car are very much impressed with the performance. Similarly Ford introduced Hydrogen combustion engine 6.8 liters V-10 engine to power E-450 Hydrogen shuttle bus. Ford modified their Gasoline engine to suit Hydrogen fuel. Substituting Gasoline with Hydrogen is no longer a theory but a commercial reality. More and more research is being undertaken to improve the performance. Currently the cost of Hydrogen cars and Hydrogen fuel is expensive, due to lack of infrastructures to manufacture such cars or to distribute Hydrogen. However these cars will soon replace gasoline cars. Similarly individual homes and business can generate their own electricity for their daily use using stored Hydrogen. Water will become the fuel of the future and Hydrogen will clean up the air that has been heavily polluted by fossil fuels for decades.